XF 1.5 Javascript error toggling smiley visibility


Well-known member
I have a lot of smilies, and now I want to remove some.
When trying to toggle the visibility of a smiley or smiley category, I get this error,

The server responded with an error. The error message is in the JavaScript console.

How can I work around this? There's far too many to delete individually. I'd prefer to hide them, but deleting is fine too.